Bonham Carter, Davis and the Phelps brothers are featured in Diagon Alley’s new retail locations and main ride, “Escape From Gringotts,” as well as the Hogwarts Express train that leaves King’s Cross Station and travels to Hogsmeade in the neighboring Islands of Adventure.

“It was fun to put on the costume again and be her,” Bonham Carter said of her role as the villainous Bellatrix Lestrange in the Gringotts ride, based on the goblin-run bank and dragon-filled adventure from the books and movies. The actress said it was touching to be asked to appear in her first theme park attraction, which she filmed two years ago.

The faithful recreation of Diagon Alley, with its restaurants like the Leaky Cauldron and Weasleys’ Wizard Wheezes magic shop, impressed the actors.

The film production, “didn’t have the resources to make every shop a reality, so it’s amazing to see it all come to life as places you can visit,” Felton said.

Guests sampled British staples like fish and chips, shepherd’s pie and pints of brews made exclusively for the park, as well as the night’s most popular item, soft-serve butterbeer ice cream.

“It’s a bit odd,” Felton said of seeing more locations from the film rebuilt as an attraction — and to attend the premiere of a new “Harry Potter” offering. “It’s nostalgic in a good way. It’s interesting to think it’s never going to end. We are going to be doing this in 10 to 15 years. There will always be fans.”

Warner Bros. CEO Kevin Tsujihara had spent the past several days visiting both parks with his daughter. “For a guy that travels a bit, it was a joy” to introduce her to the physical world of Harry Potter, he said. He thanked the fans for their loyalty to the property.

“We had a lot of concerns, so did [J.K. Rowling, who wasn’t present at the event] whether Harry Potter should even be in a theme park,” Tsujihara said. The final designs won everyone over. “When you come through the wall here you don’t feel like you’re in a theme park. That’s the most amazing part of the attraction.”

NBCUniversal vice chairman Ron Meyer called the relationship with Warner Bros. “one of the best partnerships ever,” given that it began six years ago to build the first Harry Potter park. “This has just come to life for all of us.”